Unify the tasks modal and the new session modal (#31646)

Release Notes:

- Debugger Beta: added a button to the quick action bar to start a debug
session or spawn a task, depending on which of these actions was taken
most recently.
- Debugger Beta: incorporated the tasks modal into the new session modal
as an additional tab.

---------

Co-authored-by: Julia Ryan <juliaryan3.14@gmail.com>
Co-authored-by: Julia Ryan <p1n3appl3@users.noreply.github.com>
Co-authored-by: Anthony Eid <hello@anthonyeid.me>
Co-authored-by: Mikayla <mikayla@zed.dev>

crates/debugger_ui/src/debugger_panel.rs

@@ -5,7 +5,7 @@ use crate::{
     ClearAllBreakpoints, Continue, Detach, FocusBreakpointList, FocusConsole, FocusFrames,
     FocusLoadedSources, FocusModules, FocusTerminal, FocusVariables, Pause, Restart,
     ShowStackTrace, StepBack, StepInto, StepOut, StepOver, Stop, ToggleIgnoreBreakpoints,
-    ToggleSessionPicker, ToggleThreadPicker, persistence,
+    ToggleSessionPicker, ToggleThreadPicker, persistence, spawn_task_or_modal,
 };
 use anyhow::{Context as _, Result, anyhow};
 use command_palette_hooks::CommandPaletteFilter;
@@ -65,6 +65,7 @@ pub struct DebugPanel {
     workspace: WeakEntity<Workspace>,
     focus_handle: FocusHandle,
     context_menu: Option<(Entity<ContextMenu>, Point<Pixels>, Subscription)>,
+    debug_scenario_scheduled_last: bool,
     pub(crate) thread_picker_menu_handle: PopoverMenuHandle<ContextMenu>,
     pub(crate) session_picker_menu_handle: PopoverMenuHandle<ContextMenu>,
     fs: Arc<dyn Fs>,
@@ -103,6 +104,7 @@ impl DebugPanel {
                 thread_picker_menu_handle,
                 session_picker_menu_handle,
                 _subscriptions: [focus_subscription],
+                debug_scenario_scheduled_last: true,
             }
         })
     }
@@ -264,6 +266,7 @@ impl DebugPanel {
                 cx,
             )
         });
+        self.debug_scenario_scheduled_last = true;
         if let Some(inventory) = self
             .project
             .read(cx)
@@ -1381,4 +1384,30 @@ impl workspace::DebuggerProvider for DebuggerProvider {
             })
         })
     }
+
+    fn spawn_task_or_modal(
+        &self,
+        workspace: &mut Workspace,
+        action: &tasks_ui::Spawn,
+        window: &mut Window,
+        cx: &mut Context<Workspace>,
+    ) {
+        spawn_task_or_modal(workspace, action, window, cx);
+    }
+
+    fn debug_scenario_scheduled(&self, cx: &mut App) {
+        self.0.update(cx, |this, _| {
+            this.debug_scenario_scheduled_last = true;
+        });
+    }
+
+    fn task_scheduled(&self, cx: &mut App) {
+        self.0.update(cx, |this, _| {
+            this.debug_scenario_scheduled_last = false;
+        })
+    }
+
+    fn debug_scenario_scheduled_last(&self, cx: &App) -> bool {
+        self.0.read(cx).debug_scenario_scheduled_last
+    }
 }